This invention relates to earth-working machines having loader buckets mounted at the end of their loader arm assemblies and, more particularly, to a pivot assembly for mounting the loader bucket for rotation about the end of the loader arm.
Loader buckets for earth-working machinery commonly have vertical plate-like bucket brackets integral therewith on the back side which receive a transverse pin mounted through the end of a loader arm to provide rotational motion thereabout. Typically, the pin is restrained from rotation relative to the bucket brackets as shown, for example, in Iverson et al. U.S. Pat. No. 4,096,957, to eliminate rotational wear between the pins and the brackets.
Nevertheless, even though the pin is restrained, the impact loading associated with earth-working buckets eventually causes the pin bores in the brackets to become pounded or wallowed out by the pin. Excess clearance between the pin and pin bore, as a result of manufacturing tolerances or of previous pounding, accentuates this problem and leads to loose pivots and still more severe impact loads and ultimately to failure of the bucket brackets. Others, such as the aforementioned Iverson et al. patent, have welded reinforcing rings alongside the bracket pin bores to reduce pounding. But when pounding out occurs, the pin bore in the bracket is still pounded out as well as the reinforcing rings. Moreover, it is difficult to renew the pin bore surfaces in the field because of the need to maintain axial alignment of the pin bores in each bracket.